Christ–Siemens–Touraine syndrome/hypohidrotic ectodermal dysplasia (HED) is a heterogeneous group of inherited disorders with primary defects in tissues derived from embryonic ectoderm such as hair, tooth, nail, and sweat glands. To date, more than 192 distinct disorders have been described. Here we present a case of 19-year-old female patient that manifested with HED (Christ-Siemens-Touraine syndrome).

Ectodermal dysplasia (ED) belongs to a diverse group of monogenic disorders that are characterized by defects in one or more ectodermally or mesodermally derived tissues.[1] The term “hereditary ectodermal dysplasia” was first described by Thurnam in 1848 and coined by Weech in 1929.[2] ED is divided into two categories based on the number and function of sweat glands: hidrotic ectodermal dysplasia (Clouston syndrome) and hypohidrotic/anhidrotic ectodermal dysplasia (Christ–Siemens–Touraine syndrome).[3]

Hypohidrotic ectodermal dysplasia (HED) exhibits the classic triad of hypohidrosis, hypotrichosis, and hypodontia.[4] HED is an X-linked recessive condition and the most common form of ED with significant decrease or absence of sweat glands.[5] Other features include frontal bossing, thick lips, broad depressed nasal bridge of nose and deformed ears, sparse and fine blond hair with abnormal texture of the scalp, eyebrows, and eyelashes, dry skin, and nail defects.[6],[7] Here we report a case of Christ–Siemens–Touraine syndrome in a female patient on the view of the rarity of this condition.

Case Report

A 19-year-old female patient reported to dental clinic with a chief complaint of missing tooth in lower anterior region. She also complained of dry skin and absence of sweat in her skin. She also exhibited intolerance to hot water and environment. The patient gave no history of exfoliation or extraction of teeth but gave a history of delayed eruption of teeth. No history of consanguineous marriage was reported between the parents. On general examination, it was found that she had sparse, thin, light, blond hair, scanty eyebrows and eyelashes [Figure 1], depressed nasal bridge, frontal bossing, and prominent supraorbital ridges. Lips were dry, everted, and prominent. The form of finger and toe nails did not reveal any abnormality. Intraoral examination revealed the presence of total 19 teeth along with retained deciduous teeth (81, 82, 71, and 72), which were mobile. Maxillary midline diastema was also evident [Figure 2]. The patient was subjected to radiographic examination, and panoramic radiograph revealed retained primary teeth and multiple missing permanent teeth (12, 17; 22, 26, 27; 31, 34, 35, 37; and 44, 45, 47) [Figure 3]. The erupted permanent teeth were malformed (except maxillary centrals), with hypoplastic enamel and exhibited mesiodistal reduction in tooth size. Replacement of missing teeth, intentional root canal treatment, and post and core with crown placement of centrals were the Proposed treatment plans. Extraction of deciduous teeth was carried out and prosthetic rehabilitation of the missing teeth was performed after a healing period of 3 weeks. Removal partial denture was given to the patient along with its instructions of usage. The patient was followed up for 1 month subsequent to the prosthetic rehabilitation and she did not report back further. She was also referred to a medical councilor, speech therapist, and dermatologist for advanced treatments.

The EDs are a group of inherited disorders that share in common, developmental defects involving at least two of the following structures: hair, teeth, nails, and sweat glands.[8] Pinheiro and Freire-Maia proposed the first classification system of the EDs in 1982[9] and provided additional updates in 1994 and 2001.[10]

HED is caused by mutation of a gene that encodes several proteins with roles in the ectodysplasin signal transduction pathway. Mutation in the ectodysplasin-A (EDA) gene is responsible for its X-linked recessive form. Morphogenesis of ectodermally derived structures, especially the epithelial cells of the hair follicles, sweat glands, and developing tooth germ is signaled through this pathway. This results in genetic defects leading to aplasia, hypoplasia, or dysplasia of these structures. It also leads to disturbances in the dental organ and enamel matrix formation, ensuing hypodontia and hypoplasia of teeth.[5]

HED is the most common form of ED.[11] Genetic studies of more than 300 cases have revealed X-linked mode of inheritance with its gene locus to Xq11-21.1, with females being the carriers and the condition being completely manifested in the males.[12] Female carriers are more than affected men, but they rarely present with the signs of the condition and their clinical identification is difficult.[13] Contrary to this, our case, a female patient, exhibited many clinical signs. Few studies have reported that heterozygous females display a high frequency of agenesis of permanent teeth.[14] Spontaneous gene mutation is possible and may occur in family without any previous history of the syndrome.

Extraorally fine, sparse, lusterless fair hair is seen over the scalp along with extensive scaling of the skin, and unexplained pyrexia and heat intolerance most commonly occurs because of anhidrosis. Intraorally missing permanent teeth are a common manifestation, the maxillary central incisors and canines present with a conical crown form. In rare instances, one or both jaws may be edentulous and the alveolar processes may not develop due to the absence of teeth.[15] Our case presented with missing teeth more in the mandible than in the maxilla. Most common congenitally missing teeth include third molars and maxillary lateral incisors, which are also seen associated with our case with inclusion of even the second molars. Complete anodontia of both deciduous and permanent dentition is rarely reported.[16] Significant differences in the number of primary missing teeth have been detected between X-linked HED and autosomal-recessive HED in recent investigations.[17]

The diagnosis of ED can be difficult because of a variety of types, range of abnormalities, and severity of defects. It is important to understand the genetic hereditary patterns so that the parents of an affected child can be advised on the possibility of new cases in the family.[18] Diagnosis is based on episodes of hyperpyrexia, lack of type of hair, absence of teeth and tooth buds, and tooth morphology. Structural and biochemical characteristics of hair have also been studied.[19] Other diagnostic criteria include dermatoglyphic analysis, characteristics of lacrimal secretion, and distribution and pattern of scalp hair.[20]

Cosmetic and prosthodontic measures should be carried out as early as possible to have the child resemble his peers. Management of the patient should be done by a team that includes a pediatrician, pediatric dentist, prosthodontist, dermatologist, otolaryngologist, speech therapist, and psychologist. Cephalometric analysis has shown favorable growth of maxilla and mandible following placement of dentures.[18] Relining the dentures should be performed every 1–2 years.

A correct diagnosis and treatment by the multidisciplinary approach can be helpful for the successful management of the patient.

Knowledge of such cases will enhance the awareness on its existence, early diagnosis, and treatment plan. The care administered is a combined effort of medico-dental guidance. Proper and long-term follow-up and care provided can guide these patients to lead a normal and confident life.